Handheld audio devices, such as telephone handsets, speakerphones or other audio pick-up devices, are able to use two or more microphones to perform audio processing such as echo cancellation upon audio signals received by a microphone positioned on the device to detect a user's spoken voice. Echo results from smaller and smaller phone devices mandating placement of microphones close to the telephone loudspeaker, particularly when the telephone is used in a hands-free or speakerphone mode. Sound is generated at a far-end audio source, such as the voice of the person at the other end of the phone call. This person is sometimes called the far-end talker, who speaks into a far-end telephone or a far-end device. This sound is annunciated at the loudspeaker. The sound generated by the loudspeaker is then received by the microphone or microphones of the speakerphone, resulting in a potential echo signal. Echo reduction technology, including echo cancellation and echo suppression, has been developed that intends to resolve the undesirable echo by subtracting the audio signal generated at the loudspeaker from the sound signal received by the microphone.
Speakerphones with multiple microphones intend to improve the quality of the near-end audio signals generated close to the speakerphone, such as voice sounds annunciated by one or more callers close to the speakerphone. Beamforming technology has been developed that intends to produce audio beams for enhancing the reception of audio from more desirable directions, thereby enhancing the quality of the near-end audio transmitted by the speakerphone to far-end telephones. Beamforms also have a characteristic of a spatial null where sounds in other directions are attenuated. However, in a double-talk situation where the near-end audio has a level similar to echo audio from the loudspeaker, echo reduction becomes complicated because the reflected echo and near-end audio may be more difficult for an audio signal processor to distinguish. Echo cancellation and echo suppression in a double-talk environment enhances the telephone conversation experience.